A very-low-calorie diet (VLCD), also known as semistarvation diet and crash diet, is a type of fad diet with very or extremely low daily food energy consumption. It is defined as a diet of 800 kilocalories (3,300 kJ) per day or less. Modern medically supervised VLCDs use total meal replacements, with regulated formulations in Europe and Canada which contain the recommended daily requirements for vitamins, minerals, trace elements, fatty acids, protein and electrolyte balance. Carbohydrates may be entirely absent, or substituted for a portion of the protein; this choice has important metabolic effects. Medically supervised VLCDs have specific therapeutic applications for rapid weight loss, such as in morbid obesity or before a bariatric surgery, using formulated, nutritionally complete liquid meals containing 800 kilocalories or less per day for a maximum of 12 weeks.
The routine use of VLCDs is not recommended due to safety concerns, but this approach can be used under medical supervision if there is a clinical rationale for rapid weight loss in obese individuals, as part of a "multi-component weight management strategy" with continuous support and for a maximum of 12 weeks, according to the NICE 2014 guidelines. The US dietary guidelines recommend that VLCDs can be used for weight loss in obese individuals only in limited circumstances and only under supervision by experienced personnel in a medical care setting where the individual can be medically monitored and high-intensity lifestyle intervention can be provided. For the general public, VLCDs are not recommended due to low evidence. As there are considerable risks of starvation with an inadequately composed or supervised VLCD, people attempting these diets must be monitored closely by a physician to prevent complications.
VLCDs appear to be more effective than behavioral weight loss programs or other diets, achieving approximately 4 kilograms (8.8 lb) more weight loss at 1 year and greater sustained weight loss after several years. When used in routine care, there is evidence that VLCDs achieve average weight loss at 1 year around 10 kilograms (22 lb) or about 4% more weight loss over the short term. VLCDs can achieve higher short-term weight loss compared to other more modest or gradual calorie restricted diets, and the maintained long-term weight loss is similar or greater. VLCDs were shown to reduce lean body mass. Combining VLCD with other obesity therapies yield more effective results in weight loss. Low-calorie and very-low-calorie diets may produce faster weight loss within the first 1–2 weeks of starting compared to other diets, but this superficially faster loss is due to glycogen depletion and water loss in the lean body mass and is regained quickly afterward.
A 2001 review found that VLCD has no serious harmful effect when done under medical supervision, for periods of 8–16 weeks with an average weight loss of 1.5-2.5 kg/week. However, VLCD may increase the risk of developing gallstones if the fat content of VLCD is not sufficient, but data is lacking to know the precise amount of fat that is necessary to avoid gallstones formation. Indeed, dietary fat stimulates gall bladder contraction, thus, if following a fat-free VLCD, the bladder does not empty. Another potential side effect is constipation (depending on the fiber content of the diet).
VLCD were not found to increase food cravings, and on the contrary, appear to reduce food cravings more than low-calorie diets.
Previous formulations (medical or commercial) of carbohydrate-free very low calorie diets provided 200–800 kcal/day and maintained protein intake, but eliminated any carbohydrate intake and sometimes fat intake as well. These diets subject the body to starvation and produce an average weekly weight loss of 1.5–2.5 kilograms (3.3–5.5 lb). However, the total lack of carbohydrates avoids protein sparing and thus produce a loss of lean muscle mass, as well as other adverse side effects such as increased risks of gout, and electrolyte imbalances, and are thus disadvised. Total diet replacement programs are the modern formulations regulated in Europe and Canada to ensure the recommended daily intake of necessary nutrients, vitamins and electrolyte balance. Compared to older VLCD formulas, the total diet replacements better preserve lean body mass, reduce known side effects and improve [clarify].
Unmonitored VLCDs with insufficient macronutrient and mineral intake have the potential to cause an electrolyte imbalance and sudden death via ventricular tachycardia either by starvation or upon refeeding.
History and society
The earliest data on VLCDs come from the aftermath of World War II, when several scientific experiments were undertaken to examine what conditions could lead to starvation and how to rehabilitate safely to eating, such as the Minnesota Starvation Experiment, in an effort to reduce the casualties caused by famine following the war.
VLCD is used for clinical purposes since at least the 1980s.
In 1978, 58 people died in the United States after following very-low-calorie liquid protein diets. Following this event, the FDA requires since 1984 that protein VLCDs providing fewer than 400 calories a day to carry a warning that they can cause serious illness and need to be followed under medical supervision. However, newer regulations require this warning only on protein products that aim to provide more than half of a person's calories and promoted for weight loss or as a food supplement. That way, protein VLCD drinks such as Slim-Fast, although each providing less than 400 calories, were able to avoid warnings by recommending that users "also eat one sensible meal each day".
In 1991, the Federal Trade Commission charged three liquid VLCD companies, Optifast, Medifast and Ultrafast, with deceptive advertisement, which was settled after the companies agreed to stop using what the FTC alleged as deceptive claims, about the long-term results and the safety of these diets.
- List of diets
- Management of obesity
- Negative-calorie food
- Protein-sparing modified fast, a type of very-low-calorie diet, aiming to spare proteins and thus preserve muscle tissues.
- Ahmed, W; Flynn, MA; Alpert, MA (April 2001). "Cardiovascular complications of weight reduction diets". The American Journal of the Medical Sciences (Review). 321 (4): 280–4. doi:10.1097/00000441-200104000-00007. PMID 11307868.
- "How to diet". nhs.uk. NHS. 27 April 2018.
- "Take the test: Is an 800-calorie diet right for me?". BBC Food.
- Bonet, Anna (28 November 2018). "Are crash diets ever a good idea for weight loss?". Netdoctor.
'A crash diet is typically a very low-calorie diet, where you eat a very restrictively for a short period of time,' explains Registered Dietician, Helen Bond.
- Joshi, S; Mohan, V (November 2018). "Pros & cons of some popular extreme weight-loss diets". The Indian Journal of Medical Research. 148 (5): 642–647. doi:10.4103/ijmr.IJMR_1793_18. PMC 6366252. PMID 30666989.
- "Crash dieting: Desperate measures". The Independent. 15 September 2009.
- "Crash diets can cause transient deterioration in heart function". ScienceDaily. 2018-02-02.
- Thorell, A; MacCormick, AD; Awad, S; Reynolds, N; Roulin, D; Demartines, N; Vignaud, M; Alvarez, A; Singh, PM; Lobo, DN (September 2016). "Guidelines for Perioperative Care in Bariatric Surgery: Enhanced Recovery After Surgery (ERAS) Society Recommendations". World Journal of Surgery (Professional society guidelines). 40 (9): 2065–83. doi:10.1007/s00268-016-3492-3. PMID 26943657.
- Holderbaum, M; Casagrande, DS; Sussenbach, S; Buss, C (February 2018). "Effects of very low calorie diets on liver size and weight loss in the preoperative period of bariatric surgery: a systematic review". Surgery for Obesity and Related Diseases (Systematic review). 14 (2): 237–244. doi:10.1016/j.soard.2017.09.531. PMID 29239795.
- Thom, G; Lean, M (May 2017). "Is There an Optimal Diet for Weight Management and Metabolic Health?" (PDF). Gastroenterology (Review). 152 (7): 1739–1751. doi:10.1053/j.gastro.2017.01.056. PMID 28214525.
- Howard AN (1981). "The historical development, efficacy and safety of very-low-calorie diets". International Journal of Obesity. 5 (3): 195–208. PMID 7024153.
- "Obesity: identification, assessment and management of overweight and obesity in children, young people and adults". nice.org.uk. NICE. November 2014. Retrieved 30 September 2019.
- US Department of Health and Human Services. (2017). "2015–2020 Dietary Guidelines for Americans - health.gov". health.gov. Skyhorse Publishing Inc. Retrieved 30 September 2019.
- Jensen, MD; Ryan, DH; Apovian, CM; Ard, JD; Comuzzie, AG; Donato, KA; Hu, FB; Hubbard, VS; Jakicic, JM; Kushner, RF; Loria, CM; Millen, BE; Nonas, CA; Pi-Sunyer, FX; Stevens, J; Stevens, VJ; Wadden, TA; Wolfe, BM; Yanovski, SZ; Jordan, HS; Kendall, KA; Lux, LJ; Mentor-Marcel, R; Morgan, LC; Trisolini, MG; Wnek, J; Anderson, JL; Halperin, JL; Albert, NM; Bozkurt, B; Brindis, RG; Curtis, LH; DeMets, D; Hochman, JS; Kovacs, RJ; Ohman, EM; Pressler, SJ; Sellke, FW; Shen, WK; Smith SC, Jr; Tomaselli, GF; American College of Cardiology/American Heart Association Task Force on Practice, Guidelines.; Obesity, Society. (24 June 2014). "2013 AHA/ACC/TOS guideline for the management of overweight and obesity in adults: a report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines and The Obesity Society". Circulation. 129 (25 Suppl 2): S102-38. doi:10.1161/01.cir.0000437739.71477.ee. PMC 5819889. PMID 24222017.
- Isner JM, Sours HE, Paris AL, Ferrans VJ, Roberts WC (December 1979). "Sudden, unexpected death in avid dieters using the liquid-protein-modified-fast diet. Observations in 17 patients and the role of the prolonged QT interval". Circulation. 60 (6): 1401–12. doi:10.1161/01.cir.60.6.1401. PMID 498466.
- Sours HE, Frattali VP, Brand CD, Feldman RA, Forbes AL, Swanson RC, Paris AL (April 1981). "Sudden death associated with very low calorie weight reduction regimens". The American Journal of Clinical Nutrition. 34 (4): 453–61. doi:10.1093/ajcn/34.4.453. PMID 7223697.
- Strychar I (January 2006). "Diet in the management of weight loss". CMAJ. 174 (1): 56–63. doi:10.1503/cmaj.045037. PMC 1319349. PMID 16389240.
- Parretti HM, Jebb SA, Johns DJ, Lewis AL, Christian-Brown AM, Aveyard P (March 2016). "Clinical effectiveness of very-low-energy diets in the management of weight loss: a systematic review and meta-analysis of randomized controlled trials" (PDF). Obesity Reviews. 17 (3): 225–34. doi:10.1111/obr.12366. PMID 26775902.
- Astbury NM, Aveyard P, Nickless A, Hood K, Corfield K, Lowe R, Jebb SA (September 2018). "Doctor Referral of Overweight People to Low Energy total diet replacement Treatment (DROPLET): pragmatic randomised controlled trial". BMJ. 362: k3760. doi:10.1136/bmj.k3760. PMC 6156558. PMID 30257983.
- Gudzune KA, Doshi RS, Mehta AK, Chaudhry ZW, Jacobs DK, Vakil RM, Lee CJ, Bleich SN, Clark JM (April 2015). "Efficacy of commercial weight-loss programs: an updated systematic review". Annals of Internal Medicine. 162 (7): 501–12. doi:10.7326/m14-2238. PMC 4446719. PMID 25844997.
- Clifton, PM; Keogh, JB (25 April 2018). "Effects of Different Weight Loss Approaches on CVD Risk". Current Atherosclerosis Reports. 20 (6): 27. doi:10.1007/s11883-018-0728-8. PMID 29696385. S2CID 13964240.
- Anderson JW, Konz EC, Frederich RC, Wood CL; Konz; Frederich; Wood (1 November 2001). "Long-term weight-loss maintenance: A meta-analysis of US studies". Am. J. Clin. Nutr. (Meta-analysis). 74 (5): 579–84. doi:10.1093/ajcn/74.5.579. PMID 11684524.CS1 maint: multiple names: authors list (link)
- Astrup A, Quaade F (1989). "VLCD compliance and lean body mass". International Journal of Obesity. 13 Suppl 2: 27–31. PMID 2559044.
- Alhamdan, BA; Garcia-Alvarez, A; Alzahrnai, AH; Karanxha, J; Stretchberry, DR; Contrera, KJ; Utria, AF; Cheskin, LJ (September 2016). "Alternate-day versus daily energy restriction diets: which is more effective for weight loss? A systematic review and meta-analysis". Obesity Science & Practice. 2 (3): 293–302. doi:10.1002/osp4.52. PMC 5043510. PMID 27708846.
- Koutroumanidou, E; Pagonopoulou, O (March 2014). "Combination of very low energy diets and pharmacotherapy in the treatment of obesity: meta-analysis of published data". Diabetes/Metabolism Research and Reviews (Meta-analysis). 30 (3): 165–74. doi:10.1002/dmrr.2475. PMID 24115299. S2CID 25559307.
- Mustajoki, P; Pekkarinen, T (February 2001). "Very low energy diets in the treatment of obesity". Obesity Reviews (Review). 2 (1): 61–72. doi:10.1046/j.1467-789x.2001.00026.x. PMID 12119638.
- Andersen T (July 1992). "Liver and gallbladder disease before and after very-low-calorie diets". The American Journal of Clinical Nutrition. 56 (1 Suppl): 235S–239S. doi:10.1093/ajcn/56.1.235S. PMID 1615889.
- Astrup A, Vrist E, Quaade F (February 1990). "Dietary fibre added to very low calorie diet reduces hunger and alleviates constipation". International Journal of Obesity. 14 (2): 105–12. PMID 2160441.
- Kahathuduwa, CN; Binks, M; Martin, CK; Dawson, JA (October 2017). "Extended calorie restriction suppresses overall and specific food cravings: a systematic review and a meta-analysis". Obesity Reviews (Systematic review and meta-analysis). 18 (10): 1122–1135. doi:10.1111/obr.12566. PMC 6226249. PMID 28557246.
- Howard, A. N. (1975). "Dietary Treatment of Obesity". Obesity: Its Pathogenesis And Management. Springer Netherlands. pp. 123–153. doi:10.1007/978-94-011-7155-7_5. ISBN 978-94-011-7155-7.:130–133
- Johnstone, A (May 2015). "Fasting for weight loss: an effective strategy or latest dieting trend?". International Journal of Obesity (Review). 39 (5): 727–33. doi:10.1038/ijo.2014.214. PMID 25540982. S2CID 24033290.
- Zoumbaris, Sharon K.; Bijlefeld, Marjolijn (25 November 2014). Encyclopedia of diet fads : understanding science and society (Encyclopaedia) (2nd ed.). Greenwood. ISBN 9781610697606.